Store data in tables manipulated with SQL.
Relational databases store data in tables with rows and columns, relationships through primary and foreign keys, and a declarative language SQL. Enforce integrity constraints and support transactions. Examples: PostgreSQL, MySQL, SQL Server, Oracle.
An orders table references customers by customer_id.
Relational databases store structured data reliably and let many programs share it safely, which is why they are used in most business systems.
Store data in tables manipulated with SQL.
Relational databases store structured data reliably and let many programs share it safely, which is why they are used in most business systems.
A column or set of columns that uniquely identifies each row in a table.
A column that refers to the primary key of another table, which links the data and enforces relationships.
Typical applications include storing customer and order records in tables linked by keys, recording the history of sensor readings with timestamps and keeping project data where consistency across tables matters.
Study "Cloud computing" first (topic 73 of 104 in Software & Computing). It covers the groundwork this topic builds on.
Schema. Relational algebra. Views and stored procedures.
An orders table references customers by customer_id.
The next topic is "SQL queries and joins", which builds directly on this one.
It is classed as Advanced in Software & Computing (topic 74 of 104). It is an advanced topic. It assumes you are comfortable with the intermediate topics in Software & Computing.
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